| slip up | | | |
| slip-up | | | |
| slit someone's throat | | | |
| slop bowl | | | |
| slop out | | | |
| slow burn | | | |
| slow-burn | | | |
| slow-burning | | | |
| slower than molasses | | | |
| slow march | | | |
| slow off the mark | | | |
| slow on the uptake | | | |
| slow study | | | |
| slow up | | | |
| slow-walk | | | |
| slug away | | | |
| slug it out | | | |
| slut's wool | | | |
| small change | | | |
| small dick energy | | | |
| small fry | | | |
| small potatoes | | | |
| small print | | | |
| small talk | | | |
| small wonder | | | |
| smart arse | | | |
| smart as a whip | | | |
| smart chance | | | |
| smash hit | | | |
| smashing | | | |
| smash someone's face in | | | |
| smash someone's head | | | |
| smash up | | | |
| smear campaign | | | |
| smell a rat | | | |
| smell blood | | | |
| smell fishy | | | |
| smell like a rose | | | |
| smell like a tart's handbag | | | |
| smell of an oily rag | | | |
| smell of the lamp | | | |
| smell of the shop | | | |
| smell one's own farts | | | |
| smell the barn | | | |
| smell what someone is stepping in | | | |
| smile a thousand smiles | | | |
| smile from ear to ear | | | |
| smoke-filled room | | | |
| smoke like a chimney | | | |
| smoke one's own dope | | | |
| smoke out | | | |
| smoke signal | | | |
| smoke the whole pack | | | |
| smoking gun | | | |
| smooth down | | | |
| smooth operator | | | |
| smooth sailing | | | |
| snail's pace | | | |
| snake eyes | | | |
| snake oil | | | |
| snap at | | | |
| snap at someone's heels | | | |
| snap back | | | |
| snap, crackle and pop | | | |
| snap it up | | | |
| snap judgment | | | |
| snap out of | | | |
| snap someone's head off | | | |
| snap to attention | | | |
| snatch defeat from the jaws of victory | | | |
| snatch the pebble | | | |
| snatch victory from the jaws of defeat | | | |
| sneaking suspicion | | | |
| sneak out | | | |
| sneck posset | | | |
| snedging | | | |
| sneeze on the truth | | | |
| sniff test | | | |
| snipe hunt | | | |
| snip-snap | | | |
| snitches get stitches | | | |
| snot-nosed | | | |
| snowball effect | | | |
| snowball in hell | | | |
| snowball's chance in hell | | | |
| snowed under | | | |
| snow job | | | |
| snow on the mountaintop | | | |
| snow on the rooftop | | | |
| snow out | | | |
| snuggle bunny | | | |
| soaked to the skin | | | |
| soaking wet | | | |
| soak up | | | |
| so be it | | | |
| sob story | | | |
| social death | | | |
| social ladder | | | |
| social lubricant | | | |
| sock-knocking | | | |